1. Technical Field
The present invention relates to a projection-type display device that projects light from a light source unit while modulating the light by mirrors.
2. Related Art
In projection-type display devices, light emitted from a light source unit is modulated by an electro-optical device and then the modulated light is projected in an enlarged manner by a projection optical system. In those projection-type display devices, a technology for capturing a projected image is proposed. For example, there is proposed a structure in which a projection image is captured by a camera and feedback is given to the projection image based on the image capture result (see JP-A-2013-192189 and JP-A-2015-220661). Further, there is proposed a structure in which an optical path separating element is provided between the electro-optical device and the projection optical system and light that has entered the projection-type display device from the outside via the projection optical system is guided to an image capture element via the optical path separating element (see JP-A-2004-252118).
In the structure in which a camera is added to the projection-type display device as in the structure described in JP-A-2013-192189 and JP-A-2015-220661, however, an error may occur between an image projection position and an image capture position of the camera and it is therefore difficult to accurately perform correction of the projection position or the like. When the optical path separating element is added between the electro-optical device and the projection optical system as in the structure described in JP-A-2004-252118, a problem may arise in that the light intensity of one of the projection light and the image capture light increases while the light intensity of the other decreases.